Alpha 1 drive quick question

[Dieselmadness]

Hey guys, can anyone tell me what the missing plug is in this picture? What did I plug up and where can I get one?

 

[Alumarine]

It looks like you're missing the welch plug.
On my MC1 drive it's part number 19-32652

 

[nola mike]

A ½ dollar fits that space perfectly. Ironically using actual money costs less than the actual part

 

[Scott06]

Hey guys, can anyone tell me what the missing plug is in this picture? What did I plug up and where can I get one?
View attachment 413232

Parts breakdown for your upper 3&4 are plugs for that, one is threaded and one Welch plug

https://www.marineengine.com/parts/mercruiser-sterndrive-parts/rmralpha-one-transom-assembly-19831990/6216687-thru-0d469858/driveshaft-housing-and-drive-gears